Stop Bath.. How important?

Interesting that a citric acid stop bath, if carried over can inhibit the hardening action of the fixer. One would want to be consistent if toning, then, as that will probably affect toning rates.

One of the authors is H.D.Russell -- we had a Dr John B. Russell teaching Chemistry at my university...born in Rochester, NY. might be a relation. He taught a Chemistry of Photography class...wish I had taken it.

"Today alkaline fixers have become increasingly popular for several reasons:
> No hypo required"

Should be: "No Hypo Clearing Agent required." Hypo (sodium thiosulfate) is still used.

Vaughn said:

Interesting that a citric acid stop bath, if carried over can inhibit the hardening action of the fixer. One would want to be consistent if toning, then, as that will probably affect toning rates.

One of the authors is H.D.Russell -- we had a Dr John B. Russell teaching Chemistry at my university...born in Rochester, NY. might be a relation. He taught a Chemistry of Photography class...wish I had taken it.

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Vaughn, this is interesting... nice to learn it

Vaughn said:

Should be: "No Hypo Clearing Agent required." Hypo (sodium thiosulfate) is still used.

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138S said:

Man, no muddying at all. What is missleading is saying that Acid Stop protects fixer and Water Stop not. Water stop perfectly protects fixer totally because you only carry water drops with film..

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A water stop bath on large throughput turns alkali from travel over from an alkali developer, thus making your water alkali. You are then dumping some of this into an acidic fixer, thus changing it's pH.

138S said:

Man, no muddying at all. What is missleading is saying that Acid Stop protects fixer and Water Stop not. Water stop perfectly protects fixer totally because you only carry water drops with film.

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That is not true if some developer is carried over to the fixer. You are talking about perfect conditions which cannot be blithely assumed in real world situations.

cliveh said:

A water stop bath on large throughput turns alkali from travel over from an alkali developer, thus making your water alkali. You are then dumping some of this into an acidic fixer, thus changing it's pH.

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Yes, that water should be renewed in large Labs... in the darkroom we use not noly use Water Stop one shot, even we dump water several times so only clean film arrives to fixer.

The Acid Stop bath is reused and it accumulates developer, so we end throwing dirt to the fixer, perhaps that dirt is not harmful... but personally with Water Stop for sure I find nice knowing that I'm moving only clean film to the fixer, nothing else, no chem, no acid contaninated with developer...

Sirius Glass said:

That is not true if some developer is carried over to the fixer. You are talking about perfect conditions which cannot be blithely assumed in real world situations.

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What you say is incorrect. I fill/agitate/dump the tank with fresh water 3 times... I only carry water drops to the fixer.

Instead with Stop Bath you carry acid mixed with accumulated (in the stop bath) used developer. My developer never reaches the fixer, your developer does as you reuse your Acid Stop until indicator changes the bath color. I dump the Stop Bath 3 times every processing, you accumulate used developer becuase you reuse the Stop.

Still not saying your Acid processing is wrong, sure it works perfectly, but the mine one also does.

138S said:

Yes, that water should be renewed in large Labs... in the darkroom we use not noly use Water Stop one shot, even we dump water several times so only clean film arrives to fixer.

The Acid Stop bath is reused and it accumulates developer, so we end throwing dirt to the fixer, perhaps that dirt is not harmful... but personally with Water Stop for sure I find nice knowing that I'm moving only clean film to the fixer, nothing else, no chem, no acid contaninated with developer...

What you say is incorrect. I fill/agitate/dump the tank with fresh water 3 times... I only carry water drops to the fixer.

Instead with Stop Bath you carry acid mixed with accumulated (in the stop bath) used developer. My developer never reaches the fixer, your developer does as you reuse your Acid Stop until indicator changes the bath color. i dump the Stop Bath 3 times every processing.

Still not saying your Acid processing is wrong, sure it works perfectly, but the mine one also.

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Now you are completely changing the goalposts. You are now saying you change the water regularly and you didn't mention this little fact in your previous posts. Yes, if you do that, your water stop bath should be perfectly useable.

cliveh said:

Now you are completely changing the goalposts. You are now saying you change the water regularly and you didn't mention this little fact in your previous posts. Yes, if you do that, your water stop bath should be perfectly useable.

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regularly ? Every processing dumped 3 times !!!!!

LOL, do you know many film photographers reusing a Water Stop Bath ? I'm changing nothing !!! this is common sense that the water stop is not reused... why do yo want to keep dirty water in bottles ? you just turn the tap and you fill the tank again !

In the ATL I even don't do that... the thing rinses the film with water automaticly before fixing... no bottle... I "discovered" that while processing E-6, I realized that E-6 uses a "water stop", so making an automatic rinse you not require a bottle for that.

________________________


Well, guys... instead killing horses, let's see if we can agree some conclusions:

1) With some Acid fixers an Acid Stop may be benefical to throw acid in the fixer to keep pH.

2) With Alkaline fixers just use Plain Water Stop, don't throw acid to them, sure this is not benefical and with Plain Water we get rid of a bottle.

3) Consistence is the same for Acid than for Water stops, you may shorten development a few seconds if a Water stop follows as Acid stops developent some 8 effective seconds faster.

4) That was for BW film... with BW paper Acid stop may be more suitable than water, to prevent some pitfalls.


Anything wrong in those 4 statements?

pretty good...or

1) Most fixers are designed to work with carry-over from an acidic stop bath -- some acids (e.g., citric acid) will reduce the effect of hardeners in the fixer
2) Alkaline fixers -- use a water stop bath, or water bath after an acid stop bath to maintain fixer pH
3) Being consistent with one's methods can yield consistent results
4) All bets off for silver gelatin paper processing.

I’m so confused... what should I do?

BrianShaw said:

I’m so confused... what should I do?

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For starters: stop reading 138S's posts.

Sirius Glass said:

Exceptions prove the rule. AND they are exceptions.

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pedantry warning on:
That comes from an old saying - it is "The exception proves the rule".
And that comes from old usage of the words proves and proof.
A more accurate modern translation of the old rule is "The exception tests the rule" or "The exception challenges the rule".
The most common modern example of that old use of "proof" is with alcohol products. If whisky is described as being 80 proof, it means that it tests as being 40% alcohol.
pedantry warning off.

SchwinnParamount said:

Water Vs. stop bath and film development

In the last couple of months, I've seen odd density variations in my Plus-X and FP4+. On the long edges of each frame is a subtle area of increased density which runs the lenght of the frame.

I develop in a steel tank with steel reels of course. For the last couple of years I've been using water as a stop bath as I was told I risk pinholes in the film when using stop bath of too strong a concentration. Rather than determining the correct concentration, I switched to water as it is 'supposedly' as effective as stop bath.

I switched back to stop bath for my most recent roll of film and the density problem also disappeared. There were no other process changes. Is it possible that a water stop bath is less effective in stopping development at the edges of the film where it is in contact with the reels?

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definitely possible;also if used per manufacturer's instruction,pinholes are prevented. IMHO, the use of a mild stop bath is a good idea

michael_r said:

How do you know that? It can take some time for Developer to diffuse out of the emulsion. What if fill/agitate/dump water 3 times is not enough?

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Michael, sorry if I was not clear, I follow The Darkroom Cookbook instructions. Not only I fill/agitate/dump water 3 times, I also have the film in water for 1 min at least.

TDC says:

"While a running water bath will not stop development as rapidly as an acid stop bath, it will slow it down to the point that the amount of residual development is insignificant. This is because, depending on its strength, it takes an acid stop bath approximately 15 seconds to halt development and a running water bath takes approximately 30 seconds. The difference in the negative image could not be measured. If you are still not convinced consider that the slight additional development will automatically be factored in when you run your film development test"

Page 104: https://silveronplastic.files.wordp...ookbook-3rd-ed-s-anchell-elsevier-2008-ww.pdf

Let me point that I not dump water 3 times to stop development, I do it to have the film clean and to not bring extrange chem to the fixer. The Acid Stop brings some acid and some inactivated developer, rinsing with water 3 times brings nothing to the fixer but water drops. Not saying that the contamination from an Acid Stop in the fixer is always harmful... but I prefer keeping my alkaline fixer the cleanest as possible.

As mentioned above, a mild acid fixer would also be a good idea, it is enough, no bubbles in high carbonate chem, lower acid chem transport to a potentially alkaline fixer...
_______

Above was for rolls. Furthermore, when processing (8x10") BW sheets, I open lights after the sheet has been 30 seconds in the Water Stop, my 8x10" daylight tank is a paper safe, I prefer that kind of tray development because it is daylight type and I like to control agitation (rotary can't) to obtain some highlight compensation when wanted.

After development completed I close lights and I open the safe to move the 8x10" to a tray with plain water, after some 30 seconds I open lights and I do the rest lights open, witnessing the fiixer action (clearing time). Even if development is not totally stopped after 30s there is no effect because the newly exposed crystals are nor starting their development until the induction time passes, and by then pH/agents in the emulsion have no strength.

What I do then is preparint the development of the next sheet, this is dumping the used one shot developer in the tray and pouring the following dose, washing my hands, closing lights to place the new sheet in the developer, so each 10min I make a new 8x10" sheet, each with a (potentially) different N and agitation (contary to rotary). When the new sheet is the developer's paper safe I open lights again to move the sheet in the water bath to the 1st fixer tray, just after clearing (I often measure claring time) I move that sheet to the 2nd fixer tray for an effective and perfect fixer action.

One of the reasons to not have an acid tray in this workflow is that any spill (hands contaminated with the acid stop) will ruin the sheet as contaminated surface won't develop.

I can tell that this process way is flawless, my 8x10" shots are a (low art) personal treasure one by one, because I only shot a 8x10" after a careful preparation and hauling weird heavy gear around, so I'm not to take risks in the development.

This is also convenient because lights are only closed several seconds to move the sheet in/out in the the developing safe. A very nice LF tank based on this is the Stearman Press SP-8x10 daylight processing tray that can only be recommended for its well executed effective minimalism, delivering totañ flexibility and efficiency. Nothing wrong with rotary... right now I'm personally making a JOBO ATL retrofit for good reasons...

Sirius Glass said:

For starters: stop reading 138S's posts.

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Starters should read The Darkrom Cookbook, then The Film Developing Cookbook and later the comprehensive and advanced Well Beyond Monochrome to have a well detailed map about the terrain they are walking on.

Also, do yourself a favor, instead going to personal attack, read well The Film Developing Cookbook, you'll get some technical criterion.

BrianShaw said:

I’m so confused... what should I do?

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Brian, sorry, but you are not confused, you know perfectly what you should do...

My position is that both plain water and acid will work perfectly, and you also know that.

But there are nuances...

> if using plain water stop with some not well buffered acid fixers then we may want to correct the pH of the Fixer if pH increases too much when nearing exhaustion.

> if using acid stop with some not well buffered alkaline (or neutral) fixers we may want to correct the pH of the Fixer if pH decreases to much when nearing exhaustion.

Nothing else !!!

Unless I missed it, this thread is now in Pinned mode. Wonder what is so important to make it stand/stick up front. Not arguing whether one should overuse vinegar or just use plain water. It appears both ways have be accounted for same success. The rest is just apples against more apples even, if of somewhat different taste.

And, it's getting personal for no apparent reason.

As for pinning this thread, I could list a few that are far more critical to film photography and yet some can hardly be found unless one stumbles upon them. I don't if there are rules for getting a pin, does it come in automatically after so many pages of posts? I'm honestly curious.

@138S what your quoted from me was not against anyone particular and not you for that matter, with 31 pages of posts (at this stage) relevant information is already swept under, the thread lost its informative purpose, it's gone into parallels too much, as most long threads do. And in the end there isn't all that much to talk about. Funny how some topics take a turn like this. When a thread is purely speculative in nature or simple running log of whatever that's fine, it can go on endlessly.

Here it's already long the sound of Hootie & the Blowfish, you've heard one song you've heard all of them.

I’m still learning...

Witold said:

...

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Well, if you see the last pages interesting information has been posted, for example personally I've learned that a citric stop may chage the tonning rates, also the wrong position that Acid Stop "is always better" has been weakened a lot because alkaline fixers were not counted in that "second stage".


And we got this great summary:

Vaughn said:

pretty good...or

1) Most fixers are designed to work with carry-over from an acidic stop bath -- some acids (e.g., citric acid) will reduce the effect of hardeners in the fixer
2) Alkaline fixers -- use a water stop bath, or water bath after an acid stop bath to maintain fixer pH
3) Being consistent with one's methods can yield consistent results
4) All bets off for silver gelatin paper processing.

Click to expand...

@138S Anyone looking this thread up in a few months will not benefit from few good posts on the topic, but this is how things go on a forum and finding consensus on any topic is not really possible, hence here we go and we will again.

If post could be rated on topic relevance criteria and then filter used to sort a thread in that way, it might help for future use.

I vote for this one: https://www.photrio.com/forum/threads/stop-bath-how-important.98559/page-31#post-2350160

So on the one hand, we have a chemical reaction which will very quickly neutralize the developer, and if the two are designed to work well together, should neutralize the stop as well-- total time about 30 seconds, including filling and emptying (assuming a Paterson-style tank).

On the other hand, we have a soak, rinse, repeat process that consumes 3 to 4 times as much water, takes a few minutes, and the only benefit is saving the cost of a couple tablespoons of acetic/citric acid.

It sounds to me as if the ideal process would be to use stop bath, followed by a quick rinse, which would neutralize the developer and the stop, and heavily dilute any remaining chemicals before the use of fixer-- assuming the goal is properly neutralized developer and minimal contamination of fixer.

grat said:

So on the one hand, we have a chemical reaction which will very quickly neutralize the developer, and if the two are designed to work well together, should neutralize the stop as well-- total time about 30 seconds, including filling and emptying (assuming a Paterson-style tank).

On the other hand, we have a soak, rinse, repeat process that consumes 3 to 4 times as much water, takes a few minutes, and the only benefit is saving the cost of a couple tablespoons of acetic/citric acid.

It sounds to me as if the ideal process would be to use stop bath, followed by a quick rinse, which would neutralize the developer and the stop, and heavily dilute any remaining chemicals before the use of fixer-- assuming the goal is properly neutralized developer and minimal contamination of fixer.

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Except you need to get the stop bath lined up, so in the end not much of the difference. My water flush/rinse between dev/fix is about two good fill & dump which takes about 30 sec. However, for clarity, I use exclusively one shot developers for the time being, so that makes a bit of a difference as what goes in, gets dumped straight out without trying to be cute where or what I am it at.

I stopped using Stop Bath in college when I was using TF4. Lately when I started doing more Jobo film processing stop bath made more sense. Filling and dumping a Jobo is time consuming. Now I sort of don't know why I ever stopped using stop in the first place. I think someone I trusted, well intentioned I'm sure, sold me on the idea that I should keep the process in a similar PH throughout, and that I'd save money by skipping a chemical step.

Indicator stop is cheap! Easy to use, tells you when it's exhausted. TF5 is easier to mix than TF4 and I still get to skip the Hypoclear/Permawash step. I'm pretty happy with this set up now.

Witold said:

Unless I missed it, this thread is now in Pinned mode. Wonder what is so important to make it stand/stick up front.

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The first post of the (merged) discussions dates from fifteen years ago, so you can call that a perennial question. I'm sure you could find letters to the editors in old issues of Pop Photo about the same topic, all the way to Talbot and Daguerre...

There are comparable endless discussions in sports, about specific goals or referee decisions.

Michel Hardy-Vallée said:

The first post of the (merged) discussions dates from fifteen years ago, so you can call that a perennial question. I'm sure you could find letters to the editors in old issues of Pop Photo about the same topic, all the way to Talbot and Daguerre...

There are comparable endless discussions in sports, about specific goals or referee decisions.

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Sure there are, I think I said that too.

And to add, I was suggesting post rating for relevance to the topic at hand. This or any long thread is nearly worthless in search unless someone has time to go through most posts. Rating with sort feature would allow at least to get the gist of posts. I mean in all these long threads are mostly garbage talk in one way or another.

And in this one the there not may more than two answers. There are a number of excellent posts too, but this one of those back and forth do and donts, start the counter.

"Prithee, sir, why dost thou use stop bath, when a pure aqueous solution is just as efficacious?"
-- Some random Victorian prat